Permalink
Switch branches/tags
Nothing to show
Find file Copy path
Fetching contributors…
Cannot retrieve contributors at this time
167 lines (131 sloc) 4.88 KB
<!DOCTYPE html>
<html>
<head>
<title>02.06 - Create terrain from heightmap</title>
<script src="../libs/three.js"></script>
<script src="../libs/dat.gui.min.js"></script>
<script src="../libs/chroma.min.js"></script>
<style>
body {
margin: 0;
overflow: hidden;
}
</style>
</head>
<script>
// global variables
var renderer;
var scene;
var camera;
var control;
var scale = chroma.scale(['blue', 'green', 'red']).domain([0, 50]);
function init() {
// create a scene, that will hold all our elements such as objects, cameras and lights.
scene = new THREE.Scene();
// create a camera, which defines where we're looking at.
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 10000);
// create a render, sets the background color and the size
renderer = new THREE.WebGLRenderer();
renderer.setClearColor(0x000000, 1.0);
renderer.setSize(window.innerWidth, window.innerHeight);
// add light
var light = new THREE.DirectionalLight();
light.position.set(1200, 1200, 1200);
scene.add(light);
// position and point the camera to the center of the scene
camera.position.x = 1200;
camera.position.y = 500;
camera.position.z = 1200;
camera.lookAt(scene.position);
// add the output of the renderer to the html element
document.body.appendChild(renderer.domElement);
control = new function () {
this.rotationSpeed = 0.005;
this.scale = 1;
};
addControls(control);
createGeometryFromMap();
// call the render function
render();
}
function createGeometryFromMap() {
var depth = 512;
var width = 512;
var spacingX = 3;
var spacingZ = 3;
var heightOffset = 2;
var canvas = document.createElement('canvas');
canvas.width = 512;
canvas.height = 512;
var ctx = canvas.getContext('2d');
var img = new Image();
img.src = "../assets/other/grandcanyon.png";
img.onload = function () {
// draw on canvas
ctx.drawImage(img, 0, 0);
var pixel = ctx.getImageData(0, 0, width, depth);
var geom = new THREE.Geometry;
var output = [];
for (var x = 0; x < depth; x++) {
for (var z = 0; z < width; z++) {
// get pixel
// since we're grayscale, we only need one element
var yValue = pixel.data[z * 4 + (depth * x * 4)] / heightOffset;
var vertex = new THREE.Vector3(x * spacingX, yValue, z * spacingZ);
geom.vertices.push(vertex);
}
}
// we create a rectangle between four vertices, and we do
// that as two triangles.
for (var z = 0; z < depth - 1; z++) {
for (var x = 0; x < width - 1; x++) {
// we need to point to the position in the array
// a - - b
// | x |
// c - - d
var a = x + z * width;
var b = (x + 1) + (z * width);
var c = x + ((z + 1) * width);
var d = (x + 1) + ((z + 1) * width);
var face1 = new THREE.Face3(a, b, d);
var face2 = new THREE.Face3(d, c, a);
face1.color = new THREE.Color(scale(getHighPoint(geom, face1)).hex());
face2.color = new THREE.Color(scale(getHighPoint(geom, face2)).hex())
geom.faces.push(face1);
geom.faces.push(face2);
}
}
geom.computeVertexNormals(true);
geom.computeFaceNormals();
geom.computeBoundingBox();
var zMax = geom.boundingBox.max.z;
var xMax = geom.boundingBox.max.x;
var mesh = new THREE.Mesh(geom, new THREE.MeshLambertMaterial({
vertexColors: THREE.FaceColors,
color: 0x666666,
shading: THREE.NoShading
}));
mesh.translateX(-xMax / 2);
mesh.translateZ(-zMax / 2);
scene.add(mesh);
mesh.name = 'valley';
};
}
function getHighPoint(geometry, face) {
var v1 = geometry.vertices[face.a].y;
var v2 = geometry.vertices[face.b].y;
var v3 = geometry.vertices[face.c].y;
return Math.max(v1, v2, v3);
}
function addControls(controlObject) {
}
function render() {
renderer.render(scene, camera);
requestAnimationFrame(render);
}
// calls the init function when the window is done loading.
window.onload = init;
</script>
<body>
</body>
</html>